If you’ve spotted a hole in your wall, floor, or garden and you’re wondering whether it’s a rat hole, you’re not alone. Once you realise you might have a rat problem, it’s only natural to feel a bit unsettled. These pests can cause damage, carry diseases, and leave you with that constant unease in your own home. That’s why blocking rat holes properly is one of the most important things you can do.
Let’s walk through how to find rat holes, how to block them effectively, and what else you need to do to stop rats from coming back. We’ll keep it practical and clear, and I’ll guide you through it like we’re chatting face to face.
What does a rat hole look like?
Before you block anything up, you need to be sure you’re dealing with a rat hole. Rats are clever, and they usually dig or squeeze through small spaces that lead to food, warmth, or shelter.
Here’s what to look out for:
- A hole that’s about 2–4 inches wide
- Smooth edges, often worn from repeated use
- Signs of gnawing or scratching around the hole
- Grease marks or smears along entry points
- Droppings or a musky smell nearby
Rat holes can appear in the ground (especially in gardens or along the foundations of your home), but they can also be in skirting boards, floorboards, behind kitchen units, or around pipes.
If you see a hole that matches these signs, you’ll want to act quickly. The longer it’s left, the more likely it is that rats will nest nearby or start causing trouble inside.
Why is it important to block rat holes?
Rats don’t just wander in for fun. They’re looking for warmth, food, and a safe place to hide. Once they find a hole that gives them access, they’ll keep using it. If you don’t block it off, you’re basically rolling out the red carpet for more of them.
Blocking rat holes:
- Stops rats from getting in or out
- Prevents them from setting up nests
- Cuts off access to food and water sources
- Helps you control and eventually get rid of the infestation
But there’s a right way to do it. If you block a hole without checking if a rat’s inside, you might trap it — and that could leave you with a dead rat and a whole new set of problems like smells or flies. So, timing and method matter.
How do you check if a rat hole is active?
Not all holes are being used right now. Some might be old, or used by other animals. So before you block anything, it helps to check if it’s still active.
Try this:
- Stuff the hole with newspaper or tissue – If it’s pushed out or shredded overnight, it’s likely being used
- Use flour or baby powder around the hole – You’ll spot fresh footprints if rats are passing through
- Place a camera or check regularly – If the area’s indoors, you could use a motion-activated camera or just keep an eye out
If the hole stays undisturbed for several days, it might be safe to block. But if it’s active, you’ll want to deal with the rats first.
Should you block a rat hole while the rat is still inside?
No, not unless you want to deal with a trapped rat. Rats will either gnaw their way out or die behind your wall or floorboards. Neither is a great outcome.
If you’re sure a rat is still inside the hole:
- Set traps first to catch them
- Use deterrents to drive them out (like ultrasonic repellers or natural repellents such as peppermint oil)
- Wait a few days and check the hole again
Once you’re confident the rat’s left, you can go ahead and block it up properly.
What materials can you use to block rat holes?
Rats are strong for their size, and their teeth can chew through wood, plastic, and even some metals. So if you want to seal a hole for good, you’ll need materials they can’t get through.
The best materials for blocking rat holes are:
- Wire wool (steel wool) – It’s rough, strong, and rats hate chewing through it
- Expanding foam (with caution) – Good for sealing gaps but not enough on its own. Rats can chew through it, so always pair it with something like wire wool
- Concrete or cement – Great for outdoor holes or large gaps in walls or floors
- Metal plates or mesh – Use these around vents, pipes, or structural holes where airflow is needed
- Bricks or paving slabs – Ideal for garden holes or burrows near foundations
Try combining materials where needed. For example, fill a hole with wire wool and then seal over it with concrete or strong sealant.
How do you block a rat hole indoors?
Indoor rat holes are often around pipe entry points, skirting boards, behind kitchen units, or under appliances.
Here’s how to handle them:
- Check for activity – Use flour or tissue, like we mentioned earlier
- Clean the area – Wipe away droppings, hair, or grease marks with disinfectant
- Fill the gap with wire wool – Stuff it in tight so there are no gaps
- Seal over it – Use strong caulk, plaster, or even a wooden board if the hole is large
- Check again after a few days – Make sure nothing’s trying to get back through
If the hole is around a pipe or vent, you can buy ready-made vent covers or pipe collars that are rat-proof. Just make sure you’re not cutting off airflow or blocking drainage by accident.
What’s the best way to block rat holes in your garden?
Outside, it’s a bit different. You’re dealing with soil, grass, and sometimes concrete or gravel. Rats often dig near compost bins, decking, sheds, or under walls and patios.
Here’s what to do:
- Find the entrance and any exits – Rats usually have a few routes in and out
- Disturb the tunnel – Collapse the soil slightly to see if it’s rebuilt overnight
- Wait until the hole is abandoned – You don’t want to trap anything
- Block it with heavy materials – Use bricks, gravel, and soil mixed with concrete to block the tunnel
- Compact it down – Make it as tight as possible so rats can’t dig it back out
You can also place heavy slabs or mesh on top, especially near known problem areas like sheds.
What else should you do after blocking the holes?
Blocking the hole is only part of the job. If rats found their way in once, they might try again — somewhere else. So you’ll need to deal with the cause, not just the symptom.
Here’s what to check:
- Food – Keep bins sealed tight, clear up crumbs, and store food in containers
- Water – Fix leaks and don’t leave bowls or standing water out overnight
- Shelter – Tidy up clutter, block gaps under decking or sheds, and clear overgrown plants
- Access points – Seal around doors, vents, pipes, and rooflines
If you’ve done all that and you’re still seeing signs, it might be time to speak to a pest control expert.
How long do you need to monitor after blocking a rat hole?
After blocking, keep an eye on the area for at least a week or two. You want to be sure rats aren’t coming back or trying to chew a new route in.
Watch for:
- Scratching or gnawing noises
- New droppings
- Fresh digging or signs of new holes
- Disturbed material around sealed areas
The sooner you catch a new attempt, the easier it is to stop.
Can rats chew through concrete or steel wool?
Rats can chew through a lot of things — plastic, wood, even soft metals. But they struggle with:
- Steel wool (especially if packed tightly)
- Concrete or cement
- Brick or metal mesh
That’s why it’s important to use a combination of materials. Don’t rely on foam or plastic alone — they’re quick fixes but not long-term solutions.
When should you call a professional?
If the infestation is big, if you’re still seeing signs after blocking the holes, or if you’re not sure where the rats are coming from — it’s worth getting help.
Pest control experts have the tools to find hidden nests, use bait or traps properly, and seal entry points you might miss. Plus, they can check for damage in walls, insulation, or wiring, which rats often target.
Final thoughts: sealing rat holes isn’t a one-off job
You might think blocking a hole is the end of the problem, but really, it’s just one step. To keep rats out for good, you need to block all their possible routes, take away what’s attracting them, and stay alert for signs of trouble.
If you tackle it properly — using tough materials, checking activity, and following up — you can stop rats in their tracks. You’ll make your home feel safer, cleaner, and just more comfortable again.
